1. Field of the Invention
This invention relates to earthworking apparatus and, in particular, to cutting bits for installation on a blade of such apparatus.
2. Description of the Prior Art
In U.S. Pat. No. 2,965,989, issued to M. R. Hubbard, the use of forwardly repositionable end bits for earthmoving equipment is disclosed. The Hubbard bits include a number of bolt mounting holes in excess of the minimum number required to mount the bit to the blade. This arrangement allows the bit to be selectively remounted to the blade as the cutting edge of the bit is worn away, thereby extending the useful life of the bit. The Hubbard bit is arranged to be mounted on only one or the other of the opposite corners of a blade.
In U. S. patent application Ser. No. 665,731, now U.S. Pat. No. 4,044,481, owned by the assignee of the present application, Eftefield and Lukavich disclose an end bit comprising two cutting edges extending transversely to each other and a mounting portion located between the cutting edges, the mounting portion adapted to be mounted to each of the opposite corner portions of an earthmoving blade with one or the other of the cutting edges exposed in cutting position with the remaining cutting edge in retracted position. The bit is positionable in only a single position of extension on each blade corner portion.